HTTP-on-steroids busts out of Google

Strangeloop gets SPDY

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Strangeloop – a Vancouver-based outfit offering an online service for accelerating website load times – has embraced Google's SPDY project, a new application-layer protocol designed to significantly improve the speed of good ol' HTTP.

The Canadian company claims that it's the first outfit to offer a commercial product to let you use SPDY without changes to your website. "If you're running a browser that advertises SPDY, we can instantly transfer into a SPDY connection," Strangeloop president Joshua Bixby tells The Register. "We're seeing 10 to 20 per cent speed improvements for our existing customers." At the moment, Google Chrome is the only browser that uses SPDY on the front-end.

Google first unveiled SPDY in November 2009 as an "early-stage" research project, claiming it would make the interwebs two times faster. In the lab, Google said at the time, the company saw "up to" a 55 per cent improvement when downloading the web's top 25 sites over simulated home connections.

"HTTP is an elegantly simple protocol that emerged as a web standard in 1996 after a series of experiments," Google said. "HTTP has served the web incredibly well. We want to continue building on the web's tradition of experimentation and optimization, to further support the evolution of websites and browsers."

SPDY – pronounced, yes, "speedy" – does not replace HTTP. It creates a session between the HTTP application layer and the TCP transport layer which uses an HTTP-esque request-response setup. It speeds downloading by way of multiplexed streams, request prioritization, and HTTP header compression.

"SPDY replaces some parts of HTTP, but mostly augments it," the company said. "At the highest level of the application layer, the request-response protocol remains the same. SPDY still uses HTTP methods, headers, and other semantics. But SPDY overrides other parts of the protocol, such as connection management and data-transfer formats."

At a conference last summer, Google infrastructure guru Urs Hölzle said that SPDY could reduce packet count by 40 per cent and byte count by 15 per cent, and that SDPY's header compression could reduce latency of 85 per cent. The header compression alone, he said, provided a 45 to 1142 ms improvement in page loads.

In recent months, Google has quietly rolled SPDY into its Chrome browser and at least some of its web services. In March, with a post to a Google support forum, Googler Jeff Harris said that when Chrome starts up, it enables SPDY nine out of every ten times, as it continues to test the protocol.

Naturally, Chrome users only benefit from SPDY when the browser is connecting to a site that uses the protocol as well. To date, this includes only Google services, including Gmail and Google Docs (as far as we know). But Strangeloop is now letting websites embrace the technology through its existing site-optimization service.

Strangeloop's eponymous web service – which is also available from an appliance that sits inside your own data center – optimizes website code in real time. "Our business is rewriting HTML," Bixby says. "We see an HTML page come through and we rewrite it. We change how resources are referenced, where resources are referenced. And any trick in the book we can use to make the HTML faster, we use it."

Though these optimizations occur on the fly as a webpage is being served, the service includes an "offline" component that inspects a customer's site beforehand to determine exactly which techniques should be used to improve load times. The service employs different techniques from browser to browser. In other words, when a page it fetched by Chrome, the service will optimize specifically for Chrome. This setup, Bixby says, allowed the company to relatively easily roll-in support for SPDY.

Though SPDY was developed at Google by Google alone, the company has always said that it intends to push the technology onto third-party browsers and third-party websites. Bixby says Strangeloop has worked closely with Mountain View in adding the technology to its service. "In their work with us, their objective was to get onto real-world sites," he says.

Google is often criticized for unilaterally developing and implementing SPDY and other new-age net protocols, and though Bixby understands the criticism, he also sees a need to jump-start the next generation of underlying interweb technologies. "I think some of those criticisms are valid," he says. "On the other side, you look at the evolution of TCP and HTTP over the last twenty years, and it's tough to argue that things are progressing. There has been almost no significant changes to those protocols to help with the bottlenecks we're facing." ®